How to use compound fertilizer

A compound chemical fertilizer refers to a chemical fertilizer containing two or more kinds of nutrients such as nitrogen, phosphorus and potassium. A binary compound fertilizer containing two nutrients and a ternary compound fertilizer containing three nutrients. The active ingredient of the compound fertilizer is generally expressed in terms of the corresponding percentages of N , P2O5 and K2O . According to different production methods, it can be divided into two types: compound fertilizer and mixed compound fertilizer. At present, the common chemical fertilizers commonly used in China have the following major categories:

First, binary compound fertilizer

(1) Nitrogen-phosphorus compound fertilizer Ammonium phosphate: It is a nitrogen and phosphorus binary compound chemical fertilizer popular among the masses. Its properties are relatively stable, generally grayish white or gray particles, non-hygroscopic agglomerates, soluble in water, pH value of aqueous solution . It is a chemical neutral fertilizer from 7.0 to 7.2 . Containing N12 % to 18 % containing P2O 546 % to 52 %, wherein nitrogen and phosphorus are quick-acting and easily absorbed by plants. Application method: Ammonium phosphate is a phosphorus-based nitrogen-phosphorus compound fertilizer. It is especially suitable for phosphorus-deficient soils and plants that require more phosphorus. Granular ammonium phosphate is most suitable for the application of seed fertilizers and base fertilizers. The base fertilizer is generally about 7.5 kg per mu ; the seed fertilizer is generally 2.5 to 3 kg per mu , and it should not be in direct contact with the seeds when the seed fertilizer is used, so as not to inhibit the seed germination; the topdressing application is generally 10 to 15 kg per mu, so pay attention to The ammonium phosphate should not be mixed with alkaline fertilizers such as grass ash and lime to avoid the evaporation of ammonia and the reduction of phosphorus availability.

(2) Nitrogen and potassium compound fertilizers Nitrogen and potassium fertilizers: the main components are K2SO4 and ( NH4 ) 2SO4 , containing N14 % and K2O at 11 % to 16 %. White crystal, soluble in water, low hygroscopicity. Can be used as base fertilizer, seed fertilizer and top dressing. Application method: Nitrogen and potassium compound fertilizer is especially suitable for potassium plants. The application of fertilizer on soils with nitrogen and potassium deficiency is more significant, and application on phosphorus-deficient soil should be combined with single phosphate fertilizer. The base fertilizer is generally applied about 7.5 kg per mu , the fertilizer is generally applied 2.5 to 3 kg per mu, and the topdressing is generally applied 10 to 15 kg per mu .

(III) Phosphorus-potassium compound fertilizer Potassium dihydrogen phosphate is a high-concentration phosphorus-potassium compound fertilizer that can be directly absorbed and utilized by crops. It is suitable for any soil and crop, especially for phosphorus and potassium-deficient soils and phosphorus and potassium-producing crops. . It phosphorous 22.8%, 28.6% potassium, white crystals, soluble in water, acidic, PH moisture absorption between 3-4. Application method: Potassium dihydrogen phosphate can be used as base fertilizer, top dressing and seed fertilizer, but currently only used for soaking seeds, seed dressing and fertilization outside the roots.

1 soaking method: soak seeds with 0.5 kg of potassium dihydrogen phosphate to 200 to 300 kg for about 15 hours, remove and dry, and sow.

2 Seed dressing method: Apply 125 to 300 grams of potassium dihydrogen phosphate per acre of crops , add 1.5 kg of water , mix well with seeds after melting, then simmer for 2 to 3 hours, dry and sow.

3 external fertilization: suitable concentration of external fertilization is 0.1 % to 0.3 %, spraying 50 to 75 kg per acre is appropriate, spraying period is before and after flowering, and foliage plants such as: cycad, araucaria, five needles, cedar, etc. Spraying 1 to 2 times in the growth period , 5 to 7 days apart , with strong stalks and disease resistance.

Two or three yuan compound fertilizer

Nitrogen, phosphorus and potassium compound fertilizers are chemical fertilizers containing nitrogen, phosphorus and potassium. These fertilizers are mostly compound fertilizers. Such as: N , P , K12 - 24 - 12 , 10 - 20 - 15 , 10 - 30 - 10, etc. Application method: Nitrogen, phosphorus and potassium compound fertilizers are multi-purpose, high-concentration quick-acting fertilizers, and can be used for crops such as fruit trees, seedlings, and flowers, and are generally used as base fertilizers and top dressings. For base fertilizer, 5 to 7.5 kg per acre , better for topdressing crops such as fruit trees.